Research & reports

Yann Dusza, Sébastien Barot, Yvan Kraepiel, Jean-Christophe Lata, Luc Abbadie, Xavier Raynaud · Ecology and Evolution · Global

This study examined how combinations of 20 plant species from 5 families, two substrate types (natural soil vs. artificial), and two depths (10 cm vs. 30 cm) affect green roof ecosystem functions including water retention, biomass production, nutrient cycling, and transpiration. Artificial substrates increased aboveground biomass 1.4-3.5 times relative to natural soil, and deep substrates produced 2-3 times more biomass than shallow ones on natural soil (1.4-1.9 times on artificial substrate), but no single combination of factors enhanced all studied ecosystem functions simultaneously.

· Clean Technologies and Environmental Policy · Global

Proposes an economic assessment framework aimed at achieving sustainable composting quality in low-cost, small-scale composting contexts in developing countries.

GOMGNIMBOU Alain P. K., COULIBALY Kalifa, SANON Abdramane, BACYE Bernard, Hassan NM, Sedogo P. Michel · Zenodo (CERN European Organization for Nuclear Research) · Burkina Faso

This study aimed to chemically characterize organic fertilizers used in urban agriculture in Bobo-Dioulasso, Burkina Faso. For this purpose, seven animal-based fertilizers were analyzed.

Gundula Proksch · · Global

This chapter discusses urban agriculture as a holistic approach to nutrient resource management in cities, aiming to reestablish closed-loop systems for nutrient recycling. It provides knowledge on aligning plant nutrient needs with efficient growing systems and recycling strategies like composting and anaerobic digestion. The chapter also illustrates the potential integration of these systems into building designs and their impact on building performance.

Shlrene Quaik, Kaizar Hossain, Mahamad Hakimi Ibrahim · International Journal of Agricultural Research · Global

Liquids derived from vermicomposting of pre-composted cow dung—vermiwash and vermicomposting leachate—were diluted to prevent leaf scorching and applied to sweet potato as a foliar treatment. Chemical analysis confirmed the presence of plant nutrients, and increases in chlorophyll content (chlorophyll a, b and total) and improved nutrient distribution in sweet potato leaves were observed. The results indicate vermiwash and vermicomposting leachate have potential as organic foliar fertilizers, and their application in field-scale urban farming fertigation is feasible, though enriching their nutrient content further would require adding other nutrient-rich substrates.

Sandra Yamile Salamanca Corredor, Brayan Osnaider Diaz Morales · · Colombia

This pilot study, focused on the La Estancia neighborhood of Bogotá, assessed the technical and economic feasibility of implementing home practices for utilizing household waste -- (1) vermiculture for organic waste, (2) urban agriculture and vertical gardens, and (3) reuse of greywater for non-potable uses. It also investigated whether residents of the neighborhood already use these practices for managing waste and greywater, and their level of interest in the topic.

Abdul‐Halim Abubakari, Laura Atuah, B. Banful, Hypolite Bayor · Journal of Soil Science and Environmental Management · Ghana

A study in Ghana reviewed literature and surveyed farmers on soil amendments for urban horticulture. The review found that research on soil amendments has been limited to land management and nutrient recovery, not addressing quality issues for specific production systems. Farmers adopt varying application rates due to lack of standardization, and barriers include technology for collection, funds for purchase, and labor employment.

David Mkwambisi, Andrew J. Dougill, Philip Antwi‐Agyei, C. P. Chabvuta · CABI eBooks · Malawi

Research in Lilongwe and Blantyre, Malawi, assessed urban agriculture's potential to improve soil quality, crop yields, and livelihoods. Preliminary evidence showed urban waste could address food insecurity and soil nutrient benefits, but several constraints in waste management were identified. City authorities are not proactively utilizing organic municipal waste for soil quality and agricultural production benefits.

Klaus Lorenz · Soil Science · Global

Urban agriculture (UA) engages approximately 800 million people globally and covers over 67 million hectares of urban cropland. While UA contributes to food security, growing food in urban ecosystems, particularly on degraded urban soils, presents challenges. Past research on UA has focused on social sciences, and although studies on urban soils have increased, many urban areas remain neglected. Further research and dissemination of knowledge are needed on how to maintain or enhance urban soil fertility through soil and land-use management practices.

Tovonarivo Rafolisy, Heriniaina Ramahefarison, Dominique Massé · · Madagascar (Mahajanga)

Two experiments in Mahajanga, Madagascar, compared municipal solid waste (MSW) composts with conventional organic inputs (poultry or pig manure) in leaf cropping systems over two three-month seasons. MSW composts resulted in yields higher than pig manure and urea, and similar to poultry manure. However, monitoring soil mineral nitrogen levels revealed significant accumulation under certain conditions, indicating a possible source of environmental pollution by nitrates.

А А Золотаревский, И И Прокопович · Лесной вестник / Forestry bulletin · Russia (Moscow)

This article explores the potential of composts made from woody-plant waste (WPW) as an alternative to expensive organic additives for urban gardening in Moscow. It suggests that composting WPW can provide a cost-effective solution for preparing fertile soil, which is crucial for plant survival in urban environments. Modern composting technologies allow for the mechanization of WPW composting, producing vegetable earth suitable for planting trees.

J.S.C. Wiskerke · · Global

This chapter focuses on urban food supplies and the challenges of managing waste flows from urban households and markets in developing countries. Large amounts of municipal solid waste, human excreta, and wastewater are produced, most of which end up in non-engineered landfills or pollute the urban environment. It is noted that these wastes pollute the urban environment, especially in low-income countries with less developed sanitation infrastructure.

Ermolaev E., Sundberg C., Pell M., Jönsson H. · Bioresource Technology · Sweden

Measures CH4, N2O and NH3 emissions from home composts in practice in Sweden; methane emissions were lower than in large-scale systems and increased with temperature and mixing.

Olle Lind · · Sweden (Malmö)

This study tested bokashi fermentation leachate from four food waste sources in Malmö and Lund, Sweden, on pak choi in sand, garden waste compost, and peat substrates to evaluate its potential as a biofertilizer in urban farming. The leachates were generally low in nitrogen, leading to poor plant growth in nitrogen-poor substrates, though they were high in potassium and phosphorus. Avoidable food waste contained higher sodium and chloride than unavoidable food waste, suggesting unavoidable food waste is a more suitable source for bokashi leachate fertilizer.

Yuki Sampei, Yuji Hara, Akinobu Murakami, Armand PALIJON, Kazuaki Tsuchiya, Makoto Yokohari · Journal of The Japanese Institute of Landscape Architecture · Philippines (Metro Manila)

The nitrogen supply-demand balance in compost and vegetable production on vacant lots in suburban residential districts of Quezon City, Metro Manila, was assessed. Analysis revealed that almost half of the subdivisions faced nitrogen oversupply, while several were in short supply. Current centralized composting facilities may not adequately support a continuous compost recycling system due to their distribution patterns. It was proposed that existing barangay-based policies on organic waste management and urban agriculture require greater flexibility and attention to coordination systems across subdivision boundaries.

Yuki Sampei, Yuji Hara, Akinobu Murakami, Armando M. Palijon, Kazuaki Tsuchiya, Makoto Yokohari · Institutional Repositories DataBase (IRDB) · Philippines

This study assessed the nitrogen supply-demand balance in compost and vegetable production on vacant lots in subdivisions and barangays in Quezon City, Metro Manila, using GIS. It found that nearly half of the subdivisions experienced nitrogen oversupply, while others faced shortages. Although cooperation among subdivisions within a barangay could improve nitrogen balance, the current centralized composting facilities were deemed insufficient to support a continuous compost recycling system due to their distribution patterns. The study concluded that current barangay-based policies on organic waste management and urban agriculture need greater flexibility and attention to inter-subdivision coordination across barangay boundaries.

Allan John Komakech, Noble Banadda, Joel R. Kinobe, Levi Kasisira, Cecilia Sundberg, Girma Gebresenbet, Björn Vinnerås · Journal of the Air & Waste Management Association · Uganda (Kampala)

A study characterized municipal waste in Kampala, Uganda, from July 2011 to June 2012, analyzing waste delivered to Kiteezi landfill during dry and wet months. Waste was sorted, weighed, and organic samples were analyzed for nutrients and energy content. Findings showed that organic waste constituted 88.5% in wet months and 94.8% in dry months, with an average moisture content of 71.1% and significant nutrient levels. The organic waste was concluded to be a suitable source of plant nutrients for urban agriculture, with characterization results differing from other Sub-Saharan African cities.

Guang Zhao · Applied Mechanics and Materials · Global

This paper presents a concept for building-integrated decentralized technologies for wastewater and organic waste treatment with energy and nutrient recovery, termed a "sustainable implant," for deep green housing districts. It explores the potentials of integrating solutions for energy and sanitation flows near their origin, linking sanitation to energy and food production. The system layout and dimensioning are explained, noting scale limitations and its application in a unique intentional community, with no other similar urban district-scale projects found worldwide.

Sotamenou J., Parrot L. · International Journal of Agricultural Sustainability · Cameroon (Yaoundé, Bafoussam)

A survey of 242 urban farmers in Yaoundé and Bafoussam found that 36% adopted compost (alone or mixed with inorganic fertilizers), with compost uptake driven by fertilizer expenditure, vegetable production scale, land ownership, and farm distance. The study provides policy insights for sustainable soil management in Cameroonian urban agriculture.

· International Journal of Recycling of Organic Waste in Agriculture · Global

Investigates domestic-scale vermicomposting as a low-cost, low-maintenance option for managing household solid organic waste by converting kitchen waste into worm castings.

Peter Yaw Mensah, Richard Amankwah Kuffour, Philip Kweku Baidoo, E. Awuah · Water Science & Technology · Global

A bench-scale study evaluated the effect of dewatering faecal sludge (FS) mixed with different percentages of sawdust on its microbial quality. The dewatered FS-sawdust mixture showed a significant reduction in bacterial content and helminth eggs, rendering the biosolids safe for agricultural use. Pathogen removal was highest with 150% sawdust and lowest in the 0% sawdust control.

Jimmy Álvarez Díaz, Christian Gómez, Fabián Andrés Monsalve Herrera, Monika Cristina Echavarria Pedraza · ELEMENTOS · Colombia (Bogotá)

As part of the Bogota Botanical Garden's (JBB) Urban Agriculture Project in Colombia, a small-scale closed composting device was redesigned and optimized. The research proceeded in three phases: a diagnostic assessment of the existing prototype's dimensions and handling of organic materials to evaluate product quality and identify improvements, construction of a redesigned device, and experimentation to verify its efficiency. Oxygen, pH, humidity and temperature — the factors controlling an aerobic composting process — were tracked throughout, with improvements made to the device's size, ventilation mode, thermal insulation and ease of turning to increase small-scale composting efficiency.

Jenny Calabio, Ma. Luisa Albacete · WVSU Research Journal · Philippines (Iloilo City)

This study, conducted from July 2007 to July 2008 at the Urban Agriculture Demonstration Site in La Paz, Iloilo City, evaluated soil media and ameliorants for container-grown green onion, pechay, and tomato. Pure compost was found to be the best medium for increasing yields. However, the use of IMO and rice hull as soil ameliorants did not increase yields for the three tested vegetables, and rice hull generally reduced pechay yields.

L. Gómez Tejeda · RIT Scholar Works (Rochester Institute of Technology) · Dominican Republic

The Dominican Republic's public investment in education was 2% of GNP in 2010, falling below UNESCO's 6% minimum. This pilot project, conducted at The Community for Learning School (TCFL) in the Dominican Republic during the 2011-2012 school year, enhanced 5th-8th grade science curricula with four activities: composting, a school garden, a garbage project, and an energy audit. While the school garden and composting project improved student motivation for group work and left a positive perception of environmentally friendly practices, knowledge gain about their environmental benefits was not as expected.

Mirelys Rodríguez Alfaro, Olegário Muñiz Ugarte, Bernardo Calero Martín, A. Álvarez, Francisco Martínez Rodríguez, Teudys Limeres Jiménez, Mercedes Orphee Montoya, Adriana M. de Aguilar Accioly · DOAJ (DOAJ: Directory of Open Access Journals) · Cuba

This study evaluated the heavy metal content of Cadmium, Lead, and Nickel in organic fertilizers (composts from urban solid waste) and substrates, and their effect on vegetables grown in organoponics in Havana and Guantánamo, Cuba. Composts obtained from unsorted urban solid waste and the substrates prepared from them were found to contain heavy metals, especially Cadmium and Lead, above maximum permissible limits. It was concluded that these products should not be used for food production, as these metals translocate to the edible parts of the cultivated vegetables.